I installed a 4 k ohm/coil 490R in the neck position and an 8 k ohm/coil Dirty Fingers in the bridge. And installed 2 Toneshaper CTS pull-up switch/volume control assemblies. The pull-up switches only affect the Dirty Fingers pickup. The BRIDGE pull-up puts the DF pickup in single coil mode. The NECK pull-up reverses the polaity of the DF pickup whatever mode its in, humbucker or single coil mode. The unique function happens when it's in single coil mode. When it's in single coil mode and the NECK switch is down, the DF coil closest to the bridge is hot. Then when the NECK switch is up, the DF coil closest to the neck is hot and switched into reverse polarity mode as well. So it's a totally different single coil sound.